What are the 4 kinds of PCB holes?

What are the four kinds of PCB holes

The through hole is the most common type of hole in PCB design and it runs through the entire thickness of the PCB, from the top copper foil to the bottom copper foil. Through holes are not only used for the connection between signal layers, but also often used for the connection between the power layer and the ground layer. Because it runs through all layers, manufacturing costs are low and the process is relatively simple.

A blind hole is a pass hole that only connects the PCB surface layer and a middle layer. It does not run through the entire PCB. Therefore, blind holes are very practical in multi-layer board designs, especially in high-density interconnect (HDI) designs, where they can save space: however, because the drilling process of the first hole is more complex, it is relatively more expensive than through holes.

The buried hole is similar to the blind hole, but the difference is that the buried hole is completely located in the inner layer of the PCB and cannot be seen outside. It is usually used for the connection of intermediate layer signals, mainly for the design of high density and high level PCB. Because the manufacturing process of buried holes requires higher precision, it is also more expensive than through holes.

A micropore is a type of pore with a very small aperture, usually less than 0.15 mm in diameter. It is mostly used in high-density boards (HDI) to reduce PCB area and improve signal transmission speed. Microholes are often completed through a laser drilling process and the cost is relatively high.

so ,can you tell the difference bettween the4 kinds hole?